Electrical and thermal contact for use in semiconductor devices

ABSTRACT

An electrical and thermal contact for use in a semiconductor device. The electrical and thermal contact includes an intermediate conductive layer, an insulator component, and a contact layer. The intermediate conductive layer may contact a structure of the semiconductor device. The insulator component, which is fabricated from a thermally and electrically insulative material, may be sandwiched between the intermediate conductive layer and the contact layer, which may substantially envelop the insulator component. The electrical and thermal contact may be fabricated by a process which includes forming a first thin layer on a surface of the semiconductor device, depositing a dielectric layer adjacent the first thin layer, patterning the dielectric layer to define the insulator component, forming a second thin layer adjacent the insulator component and in partial contact with the first thin layer, and patterning the first and second thin layers to define the intermediate conductive layer and the contact layer, respectively. Due to its structure, which requires relatively little electrical current to generate a desired amount of heat, the electrical and thermal contact effectively contains heat within and prevents heat from dissipating from a contacted structure, and is particularly useful for contacting and inducing a change in the electrical conductivity of structures which include phase change materials.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of application Ser. No. 09/189,098,filed Nov. 9, 1998, pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrical and thermal contact foruse in semiconductor devices. Particularly, the present inventionrelates to an electrical and thermal contact which reduces the amount ofenergy input that is required in order to switch a semiconductor devicestructure that is contacted thereto between two or more states. Morespecifically, the electrical and thermal contact of the presentinvention includes thin conductive layers which envelop an insulatorcomponent. The electrical and thermal contact is particularly useful forswitching contacted structures that include a phase change componentbetween two or more states of electrical conductivity.

2. State of the Art

Electrically erasable programmable memory devices (EEPROMS) typicallyinclude several memory elements that may be switched between a firstlogic state and a second logic state. A first logic state may be aninactive state, or an “off” state, wherein electrical impulses do nottravel across the memory element. Memory elements may be said to be in asecond logic state, such as an “activated” state or an “on” state, whenlow voltage electrical impulses (i.e., of the operational voltage of theEEPROM) will readily travel thereacross.

Memory elements may comprise fuse elements or antifuse elements. Fuseelements are programmed by “blowing” (i.e., breaking the electricalconnection across) the fuse thereof, which switches the fuse elementsfrom an active state to an inactive state. Conversely, antifuse elementsare programmed by forming a low resistance electrical path across (i.e.,activating) the antifuses thereof. The programming of both fuse andantifuse elements requires the application of a sufficient current andvoltage to such memory elements. Nevertheless, the application of toogreat a current to memory elements, such as fuse and antifuse elements,increases the potential that various other components of the EEPROM ofwhich they are a part, including without limitation the gate oxidelayer, transistors, and other structures on the surface thereof, may bedamaged.

FIG. 1 is a schematic representation of an exemplary conventionalantifuse element 1, which includes a metal contact 2, first and secondelectrodes 4 and 8, respectively, and a dielectric layer 6, whichelectrically insulates the first electrode 4 from the second electrode8. Metal contact 2 is typically a large element relative to theremainder of antifuse element 1. As a current is applied to metalcontact 2, the resistance that is generated thereby and by at least oneof the electrodes 4, 8 that are in contact therewith locally heatsdielectric layer 6, destroying at least a portion of the same andfacilitating the formation of an electrically conductive pathway betweenfirst electrode 4 and second electrode 8. Thus, an electrical contact isestablished between first and second electrodes 4 and 8, respectively,thereby activating the antifuse element.

As noted previously, programming pulses which comprise high electricalvoltages may damage various components of an EEPROM, including, withoutlimitation, the gate oxide layer, transistors and other structures onthe surface of the EEPROM. Consequently, in order to reduce thepotential for damaging EEPROMs during the programming thereof, theprogramming pulses for EEPROMs are ever-decreasing, as are the normaloperating voltages thereof. State of the art EEPROMs typically operateat either 5V or 3.3V. U.S. Pat. No. 5,486,707, issued to Kevin T. Looket al. on Jan. 23, 1996, discloses an exemplary programmable memory thatincludes antifuse elements that may be switched to an “on” state by aprogramming voltage of about 7.5V to about 10V. While in the “off”state, the electrical resistance of a typical EEPROM antifuse element ison the order of about 1 gigaohm or greater. After an antifuse of atypical state of the art EEPROM has been switched to the “on” state by aprogramming pulse, the former has a low electrical resistance, on theorder of tens of ohms or less.

The memory elements of such state of the art EEPROMs typically havelower programming voltage requirements than their predecessors, due tothe structure of the memory elements of the former and the materialsthat are utilized in the memory elements. While the programming voltagerequirements of such EEPROMs are ever-decreasing, due to the widespreaduse of conventional, low thermal impedance metal contacts in connectionwith the antifuse elements thereof, an extremely high current istypically required in order to generate a sufficient temperature toactivate such antifuse elements. Further, due to the high rate at whichmany conventional metal contacts dissipate heat, such contacts maynecessitate the input of even greater amounts of current in order toadequately heat and activate an antifuse element. Moreover, the typicaluse of conventional, relatively large metal contacts on such EEPROMs issomewhat undesirable from the standpoint that such contacts consume agreat deal of surface area or “real estate” on the surface of thesemiconductor device. Thus, conventional metal contacts limit thedensity of active device regions on the semiconductor device.

The dissipation of heat away from the memory cell through the metalcontact is especially undesirable when the memory cell includes a phasechange component, such as a chalcogenide material layer, such as theEEPROM devices disclosed in U.S. Pat. No. 5,789,758 (hereinafter “the'758 Patent”), which issued to Alan R. Reinberg on Aug. 4, 1998. As isknown in the art, chalcogenide materials and some other phase changematerials exhibit different electrical characteristics, depending upontheir state. For example, chalcogenide materials have a lower electricalconductivity in their amorphous state, or phase, than in theircrystalline state. Chalcogenide materials may be changed from anamorphous state to a crystalline state by increasing their temperature.The electrical conductivity of the material may vary incrementallybetween the amorphous state and the crystalline state.

Some EEPROMs include metal contacts that are offset from the activedevice regions of the former. Such offset contacts are said to reducethe dissipation of thermal energy from the active device regions.Although the direct dissipation of heat from the active device regionsof such EEPROM structures may be reduced, thermal energy is conducted tothe offset metal contacts, which dissipate heat at approximately thesame rate as conventionally positioned metal contacts.

Thus, an electrical and thermal contact is needed which facilitates theinput of reduced current and voltage into a structure that iselectrically contacted thereto (i.e., conserves energy) and which has alow rate of thermal dissipation relative to conventional metal contacts.A more compact electrical and/or thermal contact structure is alsoneeded.

BRIEF SUMMARY OF THE INVENTION

The electrical and thermal contact of the present invention addresseseach of the foregoing needs. The electrical and thermal contact of thepresent invention contacts a structure of a semiconductor device, suchas a phase change component of an active device region thereof, asdisclosed in the '758 Patent, and in U.S. Pat. No. 5,789,277 (“the '277Patent”), which issued to Zahorik et al. on Aug. 4, 1998, thedisclosures of both of which are hereby incorporated by reference intheir entirety. The electrical and thermal contact of the presentinvention includes an intermediate conductive layer adjacent thecontacted structure, a thermal insulator component, which is alsoreferred to as an insulator component, that is adjacent the intermediateconductive layer, and a contact layer that is adjacent the thermalinsulator component and which partially contacts the intermediateconductive layer. Preferably, the contact layer and intermediateconductive layer are in electrical and thermal communication with thecontacted structure. The thermal insulator component is preferablysandwiched between the intermediate conductive layer and the contactlayer, such that the thermal insulator component is substantiallyenveloped by the intermediate conductive and contact layers. Anexemplary active device region to which the electrical and thermalcontact of the present invention may be contacted is a memory cell, orelement, of an electrically erasable programmable memory (EEPROM)device.

Fabricating the electrical and thermal contact includes forming adielectric layer around the lateral peripheral portions of asemiconductor device structure to be contacted, patterning thedielectric layer to expose at least a portion of the semiconductordevice structure to be contacted, such as an active device regionthereof, depositing a first thin conductive layer, depositing anotherdielectric layer adjacent the first thin conductive layer, patterningthe dielectric layer to define a thermal insulator component, depositinga second thin conductive layer adjacent the thermal insulator componentand in electrical communication with the first thin conductive layer,and patterning the first and second thin conductive layers to define theintermediate conductive layer and the contact layer, respectively. Thedielectric layer is fabricated from an electrically and thermallyconductive material. Preferably, during patterning of the dielectriclayer, the first thin conductive layer is utilized as an etch stop. Theprocesses that may be employed to fabricate the electrical and thermalcontact facilitate the fabrication of a relatively small electrical andthermal contact, when compared with conventional metal contacts.

Other advantages of the present invention will become apparent to thoseof ordinary skill in the relevant art through a consideration of theensuing description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic representation of an exemplary conventionalantifuse element;

FIG. 2 is a cross-section of a contact according to the presentinvention, depicting the association of the contact with a contactedstructure on the surface of a semiconductor device;

FIG. 3 is a cross-section of a variation of the semiconductor device ofFIG. 2, the contacted structure of which includes a phase changecomponent;

FIG. 4 is a cross-section of a semiconductor device, depicting theformation of a first thin layer of electrically conductive material overthe phase change component of FIG. 3;

FIG. 5 is a cross-section of a semiconductor device, depicting theformation of a dielectric layer over the first thin layer of FIG. 4;

FIG. 6 is a cross-section of a semiconductor device, depicting thepatterning of the dielectric layer of FIG. 5;

FIG. 7 is a cross-section of a semiconductor device, depicting theformation of a second thin layer of electrically conductive materialover the patterned dielectric layer and first thin layer of FIG. 6;

FIG. 8 is a cross-section of a semiconductor device, depicting thepatterning of the first and second layers of FIG. 7;

FIG. 9 is a schematic cross-sectional representation of a semiconductordevice including a contact according to the present invention which isin contact with a memory element; and

FIGS. 10 and 11 are schematic cross-sectional representations ofalternative embodiments of the electrical and thermal contact of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises an electrical and thermal contact for acontacted structure of a semiconductor device. With reference to FIGS. 2and 3, in a preferred embodiment, the electrical and thermal contact 10is disposed on a surface 15 of a semiconductor device 14. Electrical andthermal contact 10 may be positioned adjacent a contacted structure 12,such as an antifuse or other memory element, that is exposed throughoxide layer 11, such that it electrically and thermally contacts thecontacted structure 12. Preferably, contact 10 contacts an electricallyconductive phase change component 13 of contacted structure 12 (FIG. 3),such as the memory element disclosed in the '758 Patent. Preferably,contacted structure 12 includes a dielectric element 19 surrounding thelateral peripheral portions of phase change component 13 to thermallyand electrically insulate the latter.

Electrical and thermal contact 10 includes a thin, intermediateconductive layer 16, disposed adjacent contacted structure 12, a thermalinsulator component 20 positioned adjacent the intermediate conductivelayer, and a thin, electrically conductive contact layer 22 disposedadjacent the thermal insulator component. Preferably, thermal insulatorcomponent 20 is sandwiched between intermediate conductive layer 16 andcontact layer 22, such that thermal insulator component 20 issubstantially enveloped by the intermediate and contact layers.

Phase change component 13 is preferably fabricated from an electricallyconductive phase change material, such as amorphous silicon or aso-called “chalcogenide” alloy, which typically includes at least one ofgermanium, antimony, selenium, and telurium. Such materials exhibitdifferent electrical characteristics, depending upon their state. Forexample, phase change materials such as chalcogenides exhibit greaterelectrical conductivity when in a crystalline phase than in an amorphousphase.

Intermediate conductive layer 16 is positioned such that it electricallycontacts phase change component 13 and establishes electricalcommunication between contact layer 22 and contacted structure 12.Intermediate conductive layer 16 is fabricated from an electricallyconductive material and preferably has a thickness of about 200 Å orless. Preferably, in order to maintain the structural integrity ofintermediate conductive layer 16 during the operation of semiconductordevice 14, the material from which the intermediate conductive layer isfabricated has a melting point that is higher than both the ambienttemperature at which the semiconductor device operates and the phasechange temperature of phase change component 13. An exemplary materialthat may be used to fabricate intermediate conductive layer 16 istitanium nitride (TiN), which may be deposited in highly conformallayers of about 200 Å or less by techniques that are known in the art,such as chemical vapor deposition processes. Other materials that may beused to define intermediate conductive layer 16 include, withoutlimitation, tungsten, titanium, other refractory metals, otherrefractory metal nitrides, metal alloys and other materials which areuseful as electrically conductive traces on semiconductor devices.

Thermal insulator component 20 is disposed upon intermediate conductivelayer 16, and is preferably positioned over contacted structure 12.Thermal insulator component 20 may be fabricated from a thermallyinsulative material, such as a silicon oxide (e.g., SiO₂), a dopedsilicon oxide (e.g., borophosphosilicate glass (BPSG), phosphosilicateglass (PSG), borosilicate glass (BSG)), silicon nitride, thermosetresins, thermoplastic polymers, and other dielectric materials whichexhibit good thermal insulative properties.

Contact layer 22 is preferably disposed over the entire surface ofthermal insulator component 20 and over the exposed portions ofintermediate conductive layer 16 that are adjacent to the thermalinsulator component. Contact layer 22 is fabricated from an electricallyconductive material that preferably has a thickness of about 200 Å orless. Preferably, in order to maintain the structural integrity ofcontact layer 22 during the operation of semiconductor device 14, thematerial from which the contact layer 22 is fabricated has a meltingpoint that is higher than both the ambient temperature at which thesemiconductor device operates and the phase change temperature of phasechange component 13. An exemplary material from which contact layer 22may be fabricated is titanium nitride (TiN), which may be deposited inhighly conformal layers of about 200 Å or less by techniques that areknown in the art, such as chemical vapor deposition processes.Alternatively, contact layer 22 may be manufactured from materialsincluding, without limitation, aluminum, tungsten, titanium, otherrefractory metals, other refractory metal nitrides, metal alloys andother materials that are useful as electrically conductive traces insemiconductor device applications.

Turning now to FIGS. 4 through 8, a process for fabricating electricaland thermal contact 10 is described and illustrated.

Referring now to FIG. 4, in order to form intermediate conductive layer16 (see FIGS. 2 and 3), a first thin layer 24 of thermally andelectrically conductive material is deposited on surface 15 ofsemiconductor device 14, such that it contacts portions of phase changecomponent 13 that are exposed through the oxide layer 11 of surface 15.First thin layer 24 may be formed by techniques that are known in theart which are capable of depositing an electrically conductive layerformed of a desired material and having a desirable thickness andconformity. Thin-film deposition techniques that are useful for formingfirst thin layer 24 include, without limitation, chemical vapordeposition (CVD) processes (e.g., atomospheric pressure CVD, lowpressure CVD, plasma-enhanced CVD) and sputtering, or physical vapordeposition, processes. Such techniques typically blanket-deposit a layerof the desired material over the entire surface of a semiconductordevice or larger substrate including a multitude of such devices,including any exposed contacted structures thereof.

FIG. 5 illustrates the deposition of a dielectric layer 26 adjacentfirst thin layer 24. Preferably, dielectric layer 26 is deposited uponfirst thin layer 24. As described in greater detail below, thermalinsulator component 20 (see FIGS. 2 and 3) will be defined fromdielectric layer 26. Dielectric layer 26, which comprises a thermallyinsulative material, such as those disclosed previously in reference toFIGS. 2 and 3, may be deposited adjacent first thin layer 24 across thecontact by techniques that are known to those in the art, such aschemical vapor deposition processes. Dielectric layer 26 has a thicknessthat will provide the desired amount of heat retention proximate phasechange component 13 at a desirable temperature to effect the desiredphase change and consequent change in the electrical conductivity ofphase change component 13.

With reference to FIG. 6, dielectric layer 26, which is depicted bybroken lines, is patterned to define one or more distinct thermalinsulator components 20 of desired dimensions which are positioned indesired locations upon semiconductor device 14. Processes that are knownin the art, such as masking and etching, are employed to patterndielectric layer 26 and define one or more thermal insulator components20 therefrom. Preferably, first thin layer 24 is utilized as an etchstop while defining one or more thermal insulator components 20 fromdielectric layer 26.

Turning to FIG. 7, a second thin layer 28 of thermally and electricallyconductive material is then deposited adjacent thermal insulatorcomponent 20. Second thin layer 28 is preferably deposited conformallyand in substantially uniform thickness over surface 15 of semiconductordevice 14 (or larger substrate as noted above), including substantiallyover the exposed areas of the thermal insulator component 20 and uponthe exposed portions of first thin layer 24. Second thin layer 28 may beformed by techniques that are known in the art which are capable ofdepositing an electrically conductive layer formed of a desired materialand having a desirable thickness and conformity. Thin-film depositiontechniques that are useful for forming second thin layer 28 include,without limitation, chemical vapor deposition (CVD) processes andsputtering processes. Such techniques typically blanket-deposit a layerof the desired material over the entire surface 15 of semiconductordevice 14.

Referring now to FIG. 8, first and second thin layers 24 and 28 arepatterned to define intermediate conductive layer 16 and contact layer22 of each distinct electrical and thermal contact 10 on surface 15, aswell as any electrical traces (not shown) that are in electrical contactwith the electrical and thermal contacts. First and second thin layers24 and 28 may be patterned by techniques that are known in the art, suchas masking and etching.

The processes that may be employed to fabricate electrical and thermalcontact 10 facilitate the fabrication of a structure that is relativelysmall when compared to the size of conventional metal contacts.Similarly, electrical and thermal contact 10 may be fabricated byprocesses that form and define structures of various dimensions. Thethermal and electrical conductivity of electrical and thermal contact 10is dependent upon several factors, including, without limitation, thethickness of the first and second thin layers, the height and mass ofthe thermal insulator component 20, and various characteristics of thematerials from which intermediate conductive layer 16, contact layer 22and thermal insulator component 20 are fabricated.

Referring again to FIG. 3, as noted previously, the disposition ofelectrical and thermal contact 10 adjacent and in direct contact withphase change component 13 of contacted structure 12 facilitates areduction in the overall amount of current and heat that are required tooperate or activate the contacted structure relative to the respectiveamount of current that is typically required by many semiconductordevices which include conventional heavy electrical contacts overcontacted chalcogenide memory elements. Many conventional electricalcontacts dissipate substantial amounts of thermal energy into thesurrounding environment, and thus away from the structures in contacttherewith.

In contrast, the thin electrically conductive layers (i.e., intermediateconductive layer 16 and contact layer 22) and the thermal insulatorcomponent 20 of electrical and thermal contact 10 effectively retainthermal energy in contacted structure 12. The thin intermediateconductive layer 16 and contact layer 22 each exhibit high impedancesrelative to conventional metal contacts.

As current is conveyed through contact layer 22 and intermediateconductive layer 16, thermal energy is created and absorbed by phasechange component 13. The long path lengths of layers 16 and 22 provide ahigh thermal impedance and prevent the heat generated in phase changecomponent 13 from being conducted away from phase change component 13.Thus, phase change component 13 heats to a desirable temperature (e.g.,a temperature that will switch phase change component 13 from a firstconductivity state to a second conductivity state) with a low voltageinput relative to that required by conventional metal contacts.

When phase change component 13 is heated to a sufficient temperature,thermal insulator component 20, which is proximate to phase changecomponent 13, opposite intermediate conductive layer 16, prevents heatfrom escaping into the environment surrounding thermal contact 10 and,therefore, prevents heat from escaping phase change component 13.

Thus, electrical and thermal contact 10 effectively contains thermalenergy within phase change component 13 of contacted structure 12.Moreover, due to its small surface area relative to that of conventionalmetal contacts, electrical and thermal contact 10 does not dissipateheat as quickly as conventional metal contacts. Thus, the amount ofvoltage that is required to effect a thermally-induced switching ofcontacted structure 12 from a first state to a second state is alsoreduced

FIG. 9 illustrates an exemplary use of electrical and thermal contact 10in an electrically erasable programmable memory semiconductor device 30,which is also referred to as a semiconductor device for simplicity, thatincludes a plurality of memory elements 32 (although only a singlememory element 32 is illustrated in FIG. 9). Exemplary memory elements32 with which the electrical and thermal contact 10 of the presentinvention are particularly useful include those disclosed in the '758Patent. Memory element 32 includes an upper contact electrode 36 and alower contact electrode 38, both of which may comprise a phase changematerial. As illustrated, memory element 32 also includes diffusionregions of p-doped isolation channels 39 adjacent lower contactelectrode 38, and an n-epitaxial structure 40 adjacent the p-dopedisolation channel 39. An n+ channel 41, which addresses the individualmemory cells 32, is adjacent and in electrical communication withn-epitaxial structure 40. Electrical and thermal contact 10 preferablycontacts upper contact electrode 36, which may comprise phase changecomponent 13. Although FIG. 9 illustrates a vertically contacted memoryelement 32, the electrical and thermal contact 10 of the presentinvention may also be employed in association with other memory elementdesigns or configurations, as are known to those of skill in the art, aswell as with other types of memory devices and other structures that maybe fabricated on semiconductor devices and for which an infusion ofthermal energy with a reduced, or lower, level of current input may bedesired.

With continued reference to FIG. 9, as an example of the use ofelectrical and thermal contact 10 in programming memory element 32, aprogramming impulse source 42 is placed into electrical contact withcontact layer 22. An electrical current generated by programming impulsesource 42 is then conducted through contact layer 22 and intermediateconductive layer 16, and through the phase change component 13 thereof,and causes phase change component 13 to change phase, thereby alteringthe electrical conductivity characteristics of phase change component13. Thermal insulator component 20 and low thermal conduction of uppercontact electrode 36 prevent the escape of heat from memory element 32.

Thus, self-heating of the phase change material of phase changecomponent 13, due in part to the resistivity thereof, heats memoryelement 32 to a temperature that is sufficient to activate the memoryelement and create a low resistance electrical pathway through memoryelement 32, thereby switching memory element 32 from an “off” state toan “on” state.

FIGS. 10 and 11 illustrate alternative embodiments of an electrical andthermal contact 110, 110′, respectively, which is disposed on a surface115, 115′ of a semiconductor device 114, 114′ in electrical contact witha contacted structure, such as a memory element 112, 112′ of a typeknown in the art.

Electrical and thermal contact 110, 110′ includes a thin, electricallyconductive base layer 116, 116′ disposed on surface 115, 115′ ofsemiconductor device 114, 114′ and in electrical contact with a firstconductive element 130, 130′ of memory element 112, 112′. An insulatorcomponent 120, 120′ of contact 110, 110′ is disposed on base layer 116,116′. An electrically conductive contact layer 122, 122′ is disposedadjacent insulator component 120, 120′, and in electrical contact withbase layer 116, 116′. Each of the elements of contact 110, 110 ′ may befabricated from the materials and by the processes that were discussedabove.

Memory element 112, 112′ includes a memory cell 132, 132′ in electricalcontact with first conductive element 130, 130′. Memory cell 132, 132′is fabricated as known in the art from materials such as polysiliconthat will undergo a phase change, “rupture,” or “fuse” to create ahigher or lower electrical resistance pathway upon the application of aminimum predetermined current thereto. Memory element 112′ may alsoinclude a second electrically conductive element 134′ that electricallycontacts memory cell 132′ (see FIG. 11).

As an example of the use of electrical and thermal contact 110, 110 ′ inprogramming a memory element 112, 112′, a programming impulse source 142is placed into contact with contact layer 122, 122′. An electricalcurrent that is generated by source 142, 142′ is then conducted throughcontact layer 122, 122′ to memory element 112, 112′. Heat generated inmemory element 112, 112′ causes it to switch states. The heat isprevented from leaving the memory element 112, 112′ by the low thermalconductivity of contact 110, 110′.

Although the foregoing description contains many specifics, these shouldnot be construed as limiting the scope of the present invention, butmerely as providing illustrations of some of the presently preferredembodiments. Similarly, other embodiments of the invention may bedevised which do not depart from the spirit or scope of the presentinvention. The scope of this invention is, therefore, indicated andlimited only by the appended claims and their legal equivalents, ratherthan by the foregoing description. All additions, deletions andmodifications to the invention as disclosed herein which fall within themeaning and scope of the claims are to be embraced thereby.

What is claimed is:
 1. A process for fabricating a contact on asemiconductor device, comprising: forming a first layer comprisingconductive material on a surface of the semiconductor device and inelectrical and thermal communication with a structure thereof; forming athermal insulator component substantially over said structure; forming asecond layer comprising a conductive material at least partially oversaid thermal insulator component and in communication with said firstlayer; and patterning said first layer and said second layer, said firstand second layers remaining in communication with one another.
 2. Theprocess of claim 1, wherein said forming said first layer comprisesforming at least said conductive material of said first layer to have athickness of about 200 angstroms or less.
 3. The process of claim 1,wherein said forming said thermal insulator component comprises formingsaid thermal insulator component from a material comprising at least oneof silicon oxide, thermoset resin, and thermoplastic polymer.
 4. Theprocess of claim 1, wherein said forming said thermal insulatorcomponent comprises forming a dielectric layer and patterning saiddielectric layer.
 5. The process of claim 4, wherein said patterningsaid dielectric layer comprises etching.
 6. The process of claim 5,wherein said etching comprises employing said first layer as an etchstop.
 7. The process of claim 1, wherein said forming second layercomprises forming at least conductive material of said second layer tohave a thickness of about 200 angstroms or less.
 8. The process of claim1, wherein said forming said first layer comprises disposing at leastsaid conductive material in electrical and thermal communication with aphase change component of said structure.
 9. The process of claim 8,wherein said disposing at least said conductive material of said firstlayer in electrical and thermal communication with said phase changecomponent comprises disposing at least said conductive material of saidfirst layer in electrical and thermal communication with a chalcogenidephase change component.
 10. The process of claim 8, wherein saidpatterning said dielectric layer comprises defining said thermalinsulator component at least partially over said phase change component.11. The process of claim 1, wherein said patterning said first layer andsaid second layer comprises forming an electrical trace.
 12. A methodfor thermally insulating a phase change component of a semiconductordevice structure, comprising the steps of: forming a first conductivelayer in communication with said phase change component; forming athermal insulator component over at least a portion of said firstconductive layer and positioned to at least partially thermally insulatesaid phase change component; forming a second conductive layer over saidthermal insulator component and in communication with said firstconductive layer; and patterning said first and second conductive layersso as to maintain said communication between said first and secondconductive layers.
 13. The method of claim 12, wherein said forming saidfirst conductive layer comprises disposing in communication with saidphase change component conductive material having a thickness of at mostabout 200 angstroms.
 14. The method of claim 12, wherein said formingsaid thermal insulator component comprises forming said thermalinsulator component from a material comprising at least one of siliconoxide, thermoset resin, and thermoplastic polymer.
 15. The method ofclaim 12, wherein said forming said thermal insulator componentcomprises the steps of: forming a thermal insulator layer at leastpartially over said first conductive layer; and patterning said thermalinsulator layer.
 16. The method of claim 15, wherein said patterningsaid thermal insulator layer comprises etching said thermal insulatorlayer.
 17. The method of claim 16, wherein said etching said thermalinsulator layer comprises employing said first conductive layer as anetch stop.
 18. The method of claim 12, wherein said forming said secondconductive layer comprises forming said second conductive layer to havea thickness of at most about 200 angstroms.
 19. A method for fabricatinga contact for a semiconductor device structure including a phase changecomponent, comprising the steps of: forming a first conductive structurein communication with the phase change component; forming a thermalinsulator component in contact with said first conductive structure,opposite the phase change component and positioned to at least partiallythermally insulate the phase change component; and forming a secondconductive structure in contact with said thermal insulator component,opposite said first conductive structure and in communication with saidfirst conductive structure.
 20. The method of claim 19, wherein saidforming said first conductive structure comprises the steps of:disposing a first conductive layer in communication with the phasechange component; and patterning said first conductive layer.
 21. Themethod of claim 20, wherein said forming said second conductivestructure comprises the steps of: disposing a second conductive layeradjacent said thermal insulator component, opposite one of said firstconductive layer; and patterning said second conductive layer.
 22. Themethod of claim 21, wherein said patterning said first and secondconductive layers are effected substantially concurrently.
 23. Themethod of claim 19, wherein said forming said thermal insulatorcomponent comprises the steps of: forming a thermal insulator layer; andpatterning said thermal insulator layer.
 24. The method of claim 19,wherein said forming said thermal insulator component comprises formingsaid thermal insulator component from a material comprising at least oneof silicon oxide, thermoset resin, and thermoplastic polymer.